President-elect Donald Trump’s policies on illegal immigration, particularly on the border wall and cracking down on sanctuary cities, were at the center of his election campaign. Now, advocates of immigration restriction are hoping for reform to H-1B visas that they say are hurting American workers.

The H-1B is a temporary, non-immigrant visa, currently capped at 85,000 visas a year, that allows employers to hire skilled, specialty workers on a temporary basis — particularly scientists, engineers, or computer programmers.

However, critics say that the system is rife with abuse, and is no longer a limited short-term program to help employers with unexpected labor shortages in niche areas, and has instead become a way to push out American workers in favor of cheap foreign labor.

“Because of lobbying by the Chamber of Commerce and big tech companies, they’ve succeeded in loosening standards and we’ve seen the increasingly common scenario where American workers are fired, and have to train their replacements,” Dan Stein, President of the Federation for American Immigration Reform, told FoxNews.com.

Trump has shifted stances somewhat on the visas. After initially taking a hard stance against them, in contrast to some of his Republican opponents, at a primary debate in March he appeared to change his stance and said: “I’m changing. I’m changing. We need highly skilled people in this country, and if we can’t do it, we’ll get them in.”

He later released a statement saying the H-1B program “is neither high-skilled nor immigration: these are temporary foreign workers, imported from abroad, for the explicit purpose of substituting for American workers at lower pay.”